/* ** FILES.C: A program to determine the number of file handles ** ** Released in to the Public Domain by Matthew Hunt @ 1:129/135, in the ** hopes that no "programmer" will be so lazy that he|she simple reads ** the CONFIG.SYS file ever again. ** ** Any improvements and modifications are welcome, but I ask that all ** modified versions also be placed into the Public Domain. ** ** Information on the List of Lists and SFT format was provided by ** PC Magazine November 26, 1991, and PC Interrupts by Ralf Brown ** and Jim Kyle. FILES.C was originally written for Power C. ** ** Modifications for other compiler support by Bob Stout @ 1:106/2000.6 */ #include #include "dosfiles.h" #include "mk_fp.h" /* ** Walk the SFT linked list, counting file handles as we go */ int files(void) { struct SFT_HEADER (FAR *sft); unsigned int segment, offset; int count=0; union REGS regs; struct SREGS sregs; /* Get ptr to List of Lists in ES:DX */ regs.x.ax = 0x5200; segread(&sregs); intdosx(®s, ®s, &sregs); /* Get ssss:oooo to first SFT */ segment = *((unsigned FAR *)(MK_FP(sregs.es, regs.x.bx + 6))); offset = *((unsigned FAR *)(MK_FP(sregs.es, regs.x.bx + 4))); /* Point our structure to it. */ sft = MK_FP(segment, offset); do { count += sft->number; /* Add the number of FILES */ sft = sft->next; /* Point to next one */ } while(FP_OFF(sft->next) != 0x0FFFF); /* Last one in the chain */ /* Add the FILES for the last entry */ count += sft->number; return count; } #ifdef TEST #include #include int main(void) { printf("Number of FILES entries: %d", files()); return EXIT_SUCCESS; } #endif /* TEST */
